This is perhaps the most widely known verse from the Devi Mahatmyam (Durga Saptashati). It is a refrain that appears in Chapter 11, repeated for each form in which the Goddess is present: as Shakti (power), as Buddhi (intelligence), as Nidra (sleep), as hunger, as beauty, as peace, as faith, as memory.
The teaching is radical: the Goddess is not only in temples. She is in every living being, in every form of energy and awareness. When we see strength in someone, that is Devi. When we see wisdom, that is Devi. Even hunger and sleep — these too are her forms.
The triple salutation — 'namas tasyai namas tasyai namas tasyai' — expresses complete surrender, three times over, as if one salutation could never be enough.